Mobile computing devices such as smart telephones (smartphones or apphones) include mechanisms that enable the devices to identify their geographical locations. For example, a mobile computing device can use Global Positioning System (GPS) techniques to identify the mobile computing device's geographical location. In some examples, a computing system can estimate the geographical location of a mobile computing device based on the base stations with which the mobile computing device is wirelessly communicating. In some examples, a computing system can estimate the geographical location of a mobile computing device based on the wireless routers from which the mobile computing device receives signals.